Railway signal apparatus



Marh 17, 1-931 c, KlNG 1,796,377

RAILWAY SIGNAL APPARATUS Filed May 22, 1930 INVENTOR: 351222 .E CKzzzg,

Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE I RAILWAY SIGNALAPPARATUS Application filed May 22,

My invention relates to signal apparatus adapted for use on a railwayvehicle moved ahead of a locomotive or the like equipped with meansresponsive to wayside signals for automatically producing a number ofcab signal indications and means for acltnowledging a change to a morerestrictive indication. A locomotive so equipped with automatic cabsignal devices and apparatus for acknowledging less favorable signals,such asknowledging apparatus serving to suppress the sounding of analarm or serving to forestall an automatic train stop or serving toperform other acts, customarily carries a track signal receiver on thefront end in advance of the truck wheels. When a vehicle, such as a snowplow, for example, is pushed ahead of a locomotive so equipped, the cabsignals are nullified because the forward vehicle shunts signals fromthe underlying track circuit away from the track signal receiver andrenders the latter inoperative. To equip the forward vehicle with acomplete signal receiving apparatus such as is carried on a locomotiveis a most expensive matter, and the principal object of this inventionis to provide a comparatively simple and inexpensive unit adapted to bereadily attached to any type of vehicle which may be moved ahead of alocomotive and adapted to serve not merely as a conductor fortransmitting signals from the forward vehicle to the locomotive, but asa means for checking the in tegrity of the engineer and as a safeguardin case the engineer is negligent or incapacitated.

Further objects and advantages of the invention will be apparent fromthe description which follows and which has reference to theaccompanying drawings, illustrating diagrammatically in a single figureone embodiment or example of the invention.

The apparatus shown at the left-hand side of the dot-and-dash line X-Xin the drawing represents, diagrammatically, equipment adapted to becarried on a vehicle moved ahead of a locomotive, whereas the apparatusat the right-hand side of the line XX represents diagrammaticallystandard equipment 1930. Serial No. 454,614.

now carried on a locomotive operating with a continuous inductive cabsignal system.

A track signal receiver indicated in broken lines at A is mounted on thefront end of the locomotive, and this receiver being renderedlnoperative when a vehicle is moved ahead of the locomotive, it istemporarily disconnected from the terminal board 13 on the locomotive.The instrumentalities for decoding signals transmitted from a trackcircuit to produce cab signal indications and to sound a warning alarmupon a change to a more restrictive indication are housed in a box J onthe locomotive and they form no part of this invention in the practiceof which any of the standard locomotive equipments used for this purposemay be employed. A group of conductors 1 lead from the box J to signalindicators K located in the locomotive cab, and another set ofconductors 2, 3, 4 and 5 lead to an acknowledging switch M and to magnetL. While for the sake of simplicity of illustration, magnet L isrepresented in the drawings by a conventional symbol, it is to beassumed that magnet L forms a part of an elcctro-pneumatic valve such asis commonly used in automatic train control systems and that theelectro-pneumatic valve includes a timing valve, timing reservoir andwhistle. Such valves are so designed that upon the de-energization ofthe controlling magnet the whistle is sounded, and at the expiration ofa prescribed interval, say six seconds, the timing reservoir is ventedto atmosphere and the automatic brake application efiected. When a morerestrictive signal is called to the enginemans attention by theindicators K and the sounding of the warning whistle, he may byreversing the position of the acknowledging switch M, suppress thewhistle and forestall the automatic brake application provided that theprescribed time interval has not elapsed. V

From? the terminal board B one set of conductors 6 leads to the box Jand another set of conductors 7 leads to a polarized plug connector Hcomprising a receptacle 8 mounted on the forward end of the locomotiveand a plug 9 mounted on the rear of the forward vehicle.

From thence the conduc- 1 tors 7 lead to a junction box 10 and divideinto three different groups. One group 11 leads to the track signalreceiver G mounted on the front end of the forward vehicle. Anothergroup 12 leads to the cab signal in dioators D of the forward vehicle.The third group comprises two conductors 13 and 1 1 which lead to athree-way, spring return switch E which comprises the acknowledgingdevice of the forward vehicle and which controls through a stick relay Fthe suppression of a warning whistle sounded when the magnet G isde-energized.

It will be apparent that the operation of the locomotive equipment isprecisely the same as the ordinary operation of such equipment whennothing is moved in advance of the locomotive except that the inducedsignals are received from the track circuit by the track receiver C fromwhence they are conducted to the terminal board B through the polarizedplug connector H. Upon a change to a more restrictive cab indication,the signal is visible on the indicators K and D, and the magnet L istie-energized causing the warning whistle to soi'znd and initiating anautomatic train stop. The automatic train step may, however, be defeatedby reversing the acknowledging switch M before the expiration of theprescribed interval of time required to vent the timing reservoir of theelectro-pneumatic locomotive valve. When the acknowledging switch isoperated within the prescribed period, magnet L is re-energized throughconductors 2 and 3 by means of suitable apparatus in box J, thelocomotive warning whistle is suppressed, and the automatic train stopis forestalled. Furthermore, the acknowledgment by the locomotiveengineman is independent of any acts performed on the forwa d vehicle.

However, after the more restrictive signal is receivec, the circuitincluding conductors 4 and 5 and magnet L being broken, no current flowsthrough the corresponding conductors 13 and 1- in the acknowledgingcircuit on the forward vehicle, and magnet G is tie-energizedsimultaneously with the deenergization of magnet L, sounding the warningwhistle on the forward vehicle.

Furthermore, the acknowledgment by the engineer on the locomotive willnot automatically re-energize magnet G.

After the change to a more restrictive indication has been made, therebeing no current in conductors 13 and 1 1, and hence no current inconductors 15 and 16 leading to the magnet of the stick relay F,contacts 17 and 18 are opened, as shown in the drawing; and the circuitincluding conductors 19 and 20 leading to magnet G is broken.Accordingly, when the engineer on the locomotive acknowledges byoperating switch M, this operation does not re-energize magnet G. Tosuppress the warning whistle on the forward vehicle, acknowledgingswitch E must be operated subsequent to the acknowledgment by thelocomotive engineer. When the switch E is so operated a circuit iscompleted through conductors 13 and 14: and conductors 21 and 22,re-energizing the stick relay and closing contacts 17 and 18. Withcontacts 17 and 18 closed, the return of switch E to normal position, bymeans of its spring return, re-energizes magnet G through conductors 19and 20.

It will thus be seen that the combined apparatus requires anacknowledgment first by the locomotiveengincer and then by an operatoron the forward vehicle. If the engineer should become incapacitated, orfor some other reason should fail to make proper acknowledgment of aless favorable cab signal indication, the operator on the forwardvehicle will know that acknowledgment has not been made. Accordingly theprovision of the auxiliary equipment on the forward vehicle serves tocheck the integrity of the engineer and to act as an additionalsafeguard against accident.

Furthermore, the auxiliary equipment on the forward vehicle is acomparatively simple and inexpensive apparatus which can readily beinstalled whenever occasion demands that a vehicle be pushed in advanceof a locomotive.

Having thus described my invention, I claim:

1. An apparatus adapted for use on a railway vehicle moved ahead ofanother vehicle equipped with means responsive to wayside signals forproducing a number of cab signal indications and means for acknowledginga change to a more restrictive indication; said apparatus comprising atrack receiver, a cab indicator, a circuit including a device foracknowledging a change to a more restrictive indication, conductorsleading from said track receiver, cab indicator and acknowledgingcircuit to the equipment on the vehicle in the rear, whereby the cabindicators on the forward and rear vehicle are operated simultaneouslyand complete acknowledgment is dependent upon acts performed on both vehicles.

2. An apparatus adapted for use on a railway vehicle moved ahead ofanother vehicle equipped with means responsive to wayside signals forproducing a number of cab signal indications and means for acknowledginga change to a more restrictive indication; said apparatus comprising atrack receiver, a cab indicator, a circuit including a device foracknowledging a change to a more restrictive indication, conductorsleading from said track receiver, cab indicator and acknowlec gingcircuit to the equipment on the vehicle in the rear, and meansassociated with said acknowledging device whereby when the circuit isClB-GDGlgiZGCl it cannot again be energized until acknowledgment hasbeen made on the vehicle in the rear.

3. An apparatus adapted for use on a railway vehicle moved ahead ofanother vehicle equipped with means responsive to wayside signals forproducing a number of cab signal indications and means for acknowledginga change to a more restictive indication; said apparatus including atrack receiver, an acknowledging circuit having an electricallycontrolled alarm and a device for suppressing said alarm, and meansassociated therewith whereby the alarm can only be suppressed when asimilar acknowledgment has been made on the vehicle in the rear, andconductors leading from said track receiver and acknowledging circuit tothe equipment on the vehicle in the rear.

4. An apparatus adapted for use in a railway vehicle moved ahead ofanother vehicle equipped with means responsive to wayside signals forproducing a number of cab signal indications and means for acknowledginga change to a more restrictive indication; said apparatus including atrack receiver and an acknowledging circuit having a relay-com trolledmagnet and a spring return switch, and conductors leading from saidtrack receiver and acknowledging circuit to the equipment on the vehiclein the rear, whereby the cab indicators on the forward and rear vehicleare operated simultaneously and complete acknowledgment is dependentupon acts performed on both vehicles.

5. An apparatus adapted for use on a railway vehicle moved ahead ofanother vehicle equipped with means responsive to wayside signals forproducing a number of cab signal indications and means for acknowledginga change to a more restrictive indication; said apparatus including atrack receiver and an acknowledging circuit having a magnet, a relayassociated with said magnet, a spring return switch, and means wherebysaid magnet when de-energized can only be re-energized by anacknokledgment made on the vehicle in the rear as well as by anoperation of the spring return switch on the forward vehicle.

In testimony whereof, I have hereunto signed my name at Philadelphia,Pennsylvania, this 19th day of May, 1930.

JOHN A. C. KING.

